This
well-preserved young crater, situated in crystalline bedrock of the West
African Shield, is filled almost entirely by Lake Bosumtwi, which has
a diameter of about 8 kilometers. The crater rim reaches elevations of
about 300 meters above the lake level. Chemical, isotopic, and age studies
demonstrate that the crater is the most probable source for the Ivory
Coast tektites, which are found on land in Ivory Coast, West Africa, and
as microtektites in nearby ocean sediments. The crater is excavated in
2.1–2.2-billion-year-old metasediments and metavolcanics of the
Birimian Supergroup. The target rocks do not show any unambiguous evidence
of shock metamorphism. Distinct impact-characteristic shock effects were
identified only in clasts within suevite-derived
melt fragments. The compositional range of the target rocks is significantly
wider than that of the Ivory Coast tektites, but overlaps the tektite
compositions. In this photo the crater lake is partly obscured by clouds,
which is commonly the case in the area.